A series of polyfunctional imidazole derivatives designed to permit formation of binuclear transition metal complexes bridged by deprotonated (imidazolate) imidazole rings will be synthesized. Complex formation with first row transition metal ions especially copper (II), but also cobalt and iron, will be studied by potentiometric titration and spectroscopy. Well-defined bridged binuclear ions will be subjected to complete physical characterization, especiallyby magnetic methods and esr spectroscopy to characterize the nature of metal-metal interaction in such structures. Appropriate solid complexes will be studied by X-ray diffraction and relationships between detailed coordination geometry and magnetic and spectroscopic characteristics developed.